arm64: dts: set UART1 clock frequency to 150MHz

Enable support for higher baud rates (up to 3Mbps) in UART1 - required
for bluetooth transfers.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Tested-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>